Ecosystem service supply and vulnerability to global change in Europe

Global change will alter the supply of ecosystem services that are vital for human well-being. To investigate ecosystem service supply during the 21st century, we used a range of ecosystem models and scenarios of climate and land-use change to conduct a Europe-wide assessment. Large changes in climate and land use typically resulted in large changes in ecosystem service supply. Some of these trends may be positive (for example, increases in forest area and productivity) or offer opportunities (for example, "surplus land" for agricultural extensification and bioenergy production). However, many changes increase vulnerability as a result of a decreasing supply of ecosystem services (for example, declining soil fertility, declining water availability, increasing risk of forest fires), especially in the Mediterranean and mountain regions.     

Influence of a xylanase feed additive on Lactobacillus species in the jejunum of piglets

rRNA extracts from the jejunum of rearing piglets fed a wheat/rye based diet with or without a xylanase feed additive were hybridized against eight Lactobacillus spp. specific digoxigenin labelled oligonucleotide probes. Known concentrations of sample- or culture RNA extracts were used to calibrate and quantify hybridization signals from different sample extracts and hybridizations. The xylanase feed additive tended to increase total eubacterial rRNA in the terminal jejunum, probably a result of increased Lactobacillus spp. rRNA in the central and terminal jejunum. However, individual animal variations were high. L. reuteri was the major Lactobacillus species followed by L. acidophilus and L. mucosae. L. amylophilus and L. crispatus were not detected in all RNA extracts.The results of this study show that the xylanase feed additive modifies Lactobacillus spp. populations on the species level in piglets in addition to their well known effects on digesta viscosity and nutrient digestibility.The implications of these effects for the intestinal microbiota require further analysis.     

Quantitation of the main constituents of some authentic sesame seed oils of different origin

This paper describes the composition of sesame seed oils obtained from seeds collected from five countries that are major suppliers of traded sesame seed oil. Oils were extracted from the seeds using small-scale industry pressing equipment and analyzed using standard methods for fatty acids, fatty acids in the triglyceride 2-position, tocopherols and tocotrienols, triglycerides, sterols, steradienes, and iodine value. Values for the composition of the sterols, triglycerides, fatty acids, iodine value, and tocopherol composition were generally in good agreement with the results published elsewhere. All of the oils from roasted seeds contained low levels of the sterol degradation products stigmasta-3,5-diene and campesta-3,5-diene, which were probably formed by dehydration of the parent sterols during roasting.     

Functional characterization of enone oxidoreductases from strawberry and tomato fruit

Fragaria x ananassa enone oxidoreductase (FaEO), earlier putatively assigned as quinone oxidoreductase, is a ripening-induced, negatively auxin-regulated enzyme that catalyzes the formation of 4-hydroxy-2,5-dimethyl-3(2H)-furanone (HDMF), the key flavor compound in strawberry fruit by the reduction of the alpha,beta-unsaturated bond of the highly reactive precursor 4-hydroxy-5-methyl-2-methylene-3(2H)-furanone (HMMF). Here we show that recombinant FaEO does not reduce the double bond of straight-chain 2-alkenals or 2-alkenones but rather hydrogenates previously unknown HMMF derivatives substituted at the methylene functional group. The furanones were prepared from 4-hydroxy-5-methyl-3(2H)-furanone with a number of aldehydes and a ketone. The kinetic data for the newly synthesized aroma-active substrates and products are similar to the values obtained for an enone oxidoreductase from Arabidopsis thaliana catalyzing the alpha,beta-hydrogenation of 2-alkenals. HMMF, the substrate of FaEO that is formed during strawberry fruit ripening, was also detected in tomato and pineapple fruit by HPLC-ESI-MSn and became 13C-labeled when d-[6-13C]-glucose was applied to the fruits, which suggested that a similar HDMF biosynthetic pathway occurs in the different plant species. With a database search (http://ted.bti.cornell.edu/ and http://genet.imb.uq.edu.au/Pineapple/), we identified a tomato and pineapple expressed sequence tag that shows significant homology to FaEO. Solanum lycopersicon EO (SlEO) was cloned from cDNA, and the protein was expressed in Escherichia coli and purified. Biochemical studies confirmed the involvement of SlEO in the biosynthesis of HDMF in tomato fruit.     

Extraction of isoflavone malonylglucosides from Trifolium pratense L

Extraction of isoflavone malonylglucosides from red clover (Trifolium pratense L.) is a complicated procedure. This is due to the relatively unstable character of the thermolabile glucoside malonates as well as by action of native beta-glucosidases, resulting in a rapid degradation of malonylated glucosides into their corresponding aglucones. In this study, Tris was identified as a suitable beta-glucosidase inhibitor in red clover extracts, optimized at 350 mM Tris in 80% ethanol at pH 7.2. Extraction of fresh red clover leaves using Tris increased the concentration of malonate conjugated isoflavones approximately 13 to 24 times as opposed to extraction without Tris. A comparison of isoflavone profiles obtained after extraction with and without Tris of different plant organs of red clover and several species within the family Fabaceae suggests that the amount and/or activity of the degenerative beta-glucosidase enzymes vary for the different plant parts of red clover and among the species studied. Therefore, the use of standard extraction methods may well result in overestimation of the concentration of aglucones and consequently underestimation of the malonylglucoside isoflavones concentration depending on the plant species and plant part studied.     

4-hydroxy-2,5-dimethyl-3(2H)-furanone formation by Zygosaccharomyces rouxii: effect of the medium

The formation of 4-hydroxy-2,5-dimethyl-3(2H)-furanone (HDMF) by Zygosaccharomyces rouxii was studied in yeast-peptone-dextrose medium containing d-fructose 1,6-diphosphate under various culture conditions. Cell growth and HDMF production was heavily dependent on medium pH and sodium chloride concentration. Higher pH values of the nutrient medium had a positive effect on HDMF formation but retarded cell growth resulting in an optimal pH value of 5.1 with regard to the yield of HDMF. Salt stress stimulated HDMF formation by Z. rouxii as increasing sodium chloride concentration led to higher amounts of HDMF. The HDMF concentration in the culture supernatant and HDMF formation per yeast cell peaked at 20% sodium chloride in the nutrient medium. The nonutilizable carbohydrate d-xylose displayed a weak effect on HDMF formation, and the addition of glycerol to salt-stressed cells had no effect on the production of HDMF.     

A new European land systems representation accounting for landscape characteristics

Landscape Ecology - While land use change is the main driver of biodiversity loss, most biodiversity assessments either ignore it or use a simple land cover representation. Land cover...     

Ertragssimulation mit “Ceres Wheat” an Grundwasserböden gemäßigter Klimazonen. Teil 1: Anwendungsgrenzen des Originalmodelles und Modelländerungen

Calibration of the simulation model “Ceres Wheat” under conditions of soils with shallow watertable and temperate climate. Part 1: Limitations in the applicability of the original model and necessary modifications To apply the yield simulation model “Ceres Wheat” under the specific climate conditions of Schleswig Holstein, the following modifications were necessary:

• Wheat development is strongly influenced by climatic conditions. Therefore the model has been adjusted to the temperate climate of Schleswig Holstein.
• The soil water balance routine of the model was originally designed for soils without oxygen deficiencies due to water logging. Routines for shallow water tables and artificial drainage were formulated.
• Due to modifications of the soil water balance routine, the associated nitrogen routine, especially the leaching of nitrate, has been changed.
• The simulation of yield depressions due to excessive water required the introduction of a trafficability delay function and an additional reduction factor for crop development.

All routines concerning the water and nitrogen balances and the quality of simulations have been tested under conditions of coastal marsh soils in Schleswig Holstein.     

Microbial transformation of aliphatic aldehydes by Bacillus megaterium to 2,3-dialkylacroleins

The biotransformation of a series of aliphatic aldehydes (C(8)-C(12)) by Bacillus megaterium isolated from strawberry leaf surfaces was investigated. Products were isolated by liquid/liquid extraction and analyzed by gas chromatography (GC) combined with mass spectrometry (MS). In addition to aliphatic alcohols and the remaining aldehydes, major transformation products included the corresponding acids as well as 2,3-dialkylacroleins, dehydrated aldol addition products, which were detected for the first time as biotransformation products. To verify the structures, 2,3-dialkylacroleins were chemically synthesized from the appropriate aldehydes by base-catalyzed aldol condensation reactions and characterized by (1)H and (13)C NMR spectroscopy. Time-course studies showed that the maximum yield of the acrolein derivatives was obtained after 6 days of incubation.